Status of Data Doucmentation in Power Utilities
Reliable and sufficiently detailed data is required to facilitate decision making in all activities of Distribution System Management. Controlling costs improve efficiency and reducing down time has become essential for a utility in order to successful in the highly competitive environment of today where private utilities/distribution companies are coming into distribution. With the huge connected networks, number of spur lines and alternative feeds from different sources the creation, updation and management of distribution data is a Herculean task. Many studies conducted in the utilities of the country have indicated that the data documentation in most of the utilities is very poor. The data of distribution systems is maintained through hand-drawn maps with facilities data printed in text form on them and available with the JE/linesman in charge of the feeder. These maps are rarely updated.
Data Requirements
The data requirements for management of distribution systems are voluminous and varied. Some of them are indicated below:
Consumer data
Category wise number of consumer and connected load including the Bulk Consumer’s details such as
- Contract demand
- Maximum demand
- Energy Consumption
- Supply Voltage
Demand data
- Peak demand MW/MVAR-simultaneous and non simultaneous
- Annual Energy Consumption data
Network data
- Geographical map (to scale of the area depicting Transmission and Sub-transmission system).
- Source (s) of power supply/Grid substation (s) supplying power to the area
- Existing Substation
- Existing lines
Sub-Transmission System
- Existing 66-33/11 kV Sub-Stations & Existing 66-33 kV LINES.
- Under Construction Sub-Station.
- Under Construction 66/33/11 kV lines.
Distribution System
- 11kV lines
- Distribution transformers
- LT lines.
Operational parameters
- Substation equipment status
- 66/33 kV Feeder breakdowns
- Failure of distribution transformers
- Tripping on 11 KV feeders/lines
- Consumer outages
Electrical network details
- Electrical network details – single line diagrams with conductor sizes, lengths, transformer locations, capacitors, capacitors, consumer location and load etc.
- Parameters of equipments, devices and conductors
- Load data-peak load, diversity factor, power factor etc.
LV Network
- Section length
- Conductor size of each section
- Connected load for each group of consumer
- Number of consumers in each group
- Total connected load on the transformer
Equipment Parameter Data
The Schematic diagram for existing sub-stations are to be prepared with information of power transformer rating and numbers, impedance values, bus bar scheme, isolators, circuit breakers type e.g. minimum oil/bulk oil/SF6/Vaccum and type of installation (indoor/outdoor), no of incoming and outgoing feeders, CTs and PTs, details of taps and normal tap position, spare bays etc.
Load Data
The load data covering the monthly, daily and yearly details of energy/peak power in the electrical system as well as information as below is required:
- Peak load on each transformer/feeder and corresponding actual voltage.
- Diversity factor at various voltage levels.
- Power factor at various voltage levels
- Load factor and loss load factor at various voltage levels.
Further data on billing, revenue collection, pending applications investment, material & manpower requirements etc are some of the other data required. As can be seen, the data requirement is very voluminous. These records have to be stored, retrieved and used by many different, people at different locations. If manual records are used, then there is every likely hood of these records getting displaced or destroyed. The use of advanced information technology tools for maintaining a coherent database becomes very essential.